Poor Sound on DVD

I wonder if anyone can help me with this problem, I have a Panason Nicam TV but when I play a DVD the sound is very poor, very low volume. I have it connected with a scart lead. I have tried 2 different DVD players 2 different scart leads, I have also tried swapping the scart leads at the back of the set to no avail. I have 2 scart sockets on the back of the set, the Sky and VCR are connected to one and the DVD to the other, I just don’t know what to do now it’s driving me mad, I thought it was a problem with the scart lead so I bought a good one, I also tried another DVD player thinking this was the problem I’m running out of options, is there a magical cure?